Export the username environment variable. This to be sure that you are going to create the correct objects.
export USER_NAME=<username>
For this lab we are going to create fresh project. Use the following command.
oc new-project lab-05-${USER_NAME}
Or, of course, create the lab-05-${USER_NAME} project through the UI.
If you deploy an application with Openshift it is very easy to create an autoscaler. Autoscalers are used when for example the CPU load of a pod is equal or above 80%. This is a treshold that you can configure in the Openshift web console.
First create a new application from the catalog. We will choose a simple Jenkins
deployment.
Click on the normal Jenkins (Ephemeral) app and just click Next. Now click Create and
Create Anyway afterwards click Close. You will be able to see in the dashboard
that a new application has been created in the project.
Before you continue with the next steps you will have to wait a little for Jenkins to get deployed.
Navigate to Applications Pods and you will see that there is one pod running.
There will be 2 pods, but one will be completed. This was for the build of the
application and is not used anymore.
Navigate to Applications Deployments and click on the jenkins
deployment. Navigate to the Configuration tab and you will see on the right
side an option Autoscaling click on Add Autoscaler.
Fill in the parameters for Min Pods and Max Pods. To be able to see the change
we will put the Min Pods on 2 and the Max Pods on 3. The CPU Request Target
is going to be 80%. Obviously you can put either value you want in here. Depending
on the kind of application you are running.
Click Save and you will get the message that the horizontal autoscaling for
jenkins is successful.
You will notice a warning:
Warning: This deployment config does not have any containers with a CPU request
set. Autoscaling will not work without a CPU request. Edit Resource Requests and
Limits
Click the Edit Resource Requests and Limits link and set a CPU limit of 100
milicores. The warning message should now have dissapeared.
When you navigate to Applications Pods you will now notice that a second pod
is preparing.This could take a minute. When this is done you will have the 2
minimum pods of the jenkins instance.
Delete your project with the following command.
oc delete project lab-05-${USER_NAME}